use std::ptr;

const NUM_TEST_VALUES: usize = 10_000;

extern "C" {
    fn alloc_test_set_limit(alloc_count: isize);
}

#[repr(C)]
struct BinomialHeap<T> {
    // Define the fields of BinomialHeap here
    // This is a placeholder for the actual implementation
}

enum HeapType {
    Min,
    Max,
}

impl<T: Ord + Clone> BinomialHeap<T> {
    fn new(heap_type: HeapType) -> Self {
        // Implement the constructor here
        unimplemented!()
    }

    fn insert(&mut self, value: T) -> bool {
        // Implement the insert method here
        unimplemented!()
    }

    fn pop(&mut self) -> Option<T> {
        // Implement the pop method here
        unimplemented!()
    }

    fn num_entries(&self) -> usize {
        // Implement the num_entries method here
        unimplemented!()
    }
}

fn generate_heap() -> BinomialHeap<i32> {
    let mut heap = BinomialHeap::new(HeapType::Min);
    for i in 0..NUM_TEST_VALUES {
        if i != TEST_VALUE {
            assert!(heap.insert(i));
        }
    }
    heap
}

fn verify_heap(heap: &mut BinomialHeap<i32>) {
    let num_vals = heap.num_entries();
    assert_eq!(num_vals, NUM_TEST_VALUES - 1);

    for i in 0..NUM_TEST_VALUES {
        if i == TEST_VALUE {
            continue;
        }

        let val = heap.pop().unwrap();
        assert_eq!(val, i);
        assert_eq!(heap.num_entries(), num_vals - 1);
    }
}

fn test_insert_out_of_memory() {
    for i in 0..6 {
        unsafe { alloc_test_set_limit(i as isize); }
        let mut heap = generate_heap();

        assert!(!heap.insert(TEST_VALUE));
        unsafe { alloc_test_set_limit(-1); }

        verify_heap(&mut heap);
    }
}

fn test_pop_out_of_memory() {
    for i in 0..6 {
        unsafe { alloc_test_set_limit(i as isize); }
        let mut heap = generate_heap();

        assert!(heap.pop().is_none());
        unsafe { alloc_test_set_limit(-1); }

        drop(heap);
    }
}

type UnitTestFunction = fn();

fn run_tests(tests: &[Option<UnitTestFunction>]) {
    for test in tests.iter() {
        if let Some(t) = test {
            t();
        } else {
            break;
        }
    }
}

const TEST_VALUE: usize = NUM_TEST_VALUES / 2;

static TESTS: [Option<fn()>; 6] = [
    Some(test_binomial_heap_new_free),
    Some(test_binomial_heap_insert),
    Some(test_min_heap),
    Some(test_max_heap),
    Some(test_insert_out_of_memory),
    Some(test_pop_out_of_memory),
];

fn main() {
    run_tests(&TESTS);
}

// Placeholder implementations for the tests
fn test_binomial_heap_new_free() {}
fn test_binomial_heap_insert() {}
fn test_min_heap() {}
fn test_max_heap() {}
